***
Under EU Distance Selling legislation you can send an item back for any reason if you could not inspect it before purchase and you paid a fixed price. This legislation does not apply to auctions (including eBay auctions) - if you win an eBay auction, that is a legally binding contract, and you cannot just decide you do not want the item, and breach the contract - regardless of how you choose to pay.
But if an item is wrongly described you can seek to get your money back in any sale, of course - however, you need to prove that it is wrongly described (in court if necessary).
Alan